Disordered eating behaviour is associated with blunted cortisol and cardiovascular reactions to acute psychological stress

The behavioural, cognitive, and neural corollaries of blunted cardiovascular and cortisol reactions to acute psychological stress

Recent research shows that blunted cardiovascular and cortisol reactions to acute psychological stress are associated with adverse behavioural and health outcomes: depression, obesity, bulimia, and addictions. These outcomes may reflect suboptimal functioning of the brain's fronto-limbic systems that are needed to regulate motivated behaviour in the face of challenge. In support of this, brain imaging data demonstrate fronto-limbic hypoactivation during acute stress exposure. Those demonstrating blunted reactions also show impairments of motivation, including lower cognitive ability, more rapid cognitive decline, and poorer performance on motivation-dependent tests of lung function. Persons exhibiting blunted stress reactivity display well established temperament characteristics, including neuroticism and impulsivity, characteristic of various behavioural disorders. Notably, the outcomes related to blunted stress reactivity are similar to those that define Reward Deficiency Syndrome. Accordingly, some individuals may be characterised by a broad failure in cardiovascular and cortisol responding to both stress and reward, reflecting fronto-limbic dysregulation. Finally, we proffer a model of blunted stress reactivity, its antecedents and sequelae, and identify future research priorities.

Perinatal hypothalamic-pituitary-adrenal axis regulation among women with eating disorders and their infants

BACKGROUND

Psychiatric illness is associated with heightened hypothalamic-pituitary-adrenal (HPA) axis activity during pregnancy which may have long term effects on infant stress regulation. HPA axis regulation has not previously been investigated in women with eating disorders (ED) or their infants during the perinatal period.

METHODS

Women were recruited to a prospective longitudinal study in three groups: 1) current or active ED (C-ED=31), 2) past ED (P-ED=29) and healthy control (HC=57). Maternal psychopathology, diurnal cortisol levels, corticotropin-releasing hormone (CRH) and CRH binding protein (CRH-BP) were measured during the third trimester of pregnancy. At eight weeks postpartum infant cortisol was obtained before and after routine immunisations to determine infant hormonal response to a stressful situation.

RESULTS

Women with current ED had a significantly lower cortisol decline throughout the day compared to HC, in both adjusted and unadjusted analyses. Lower cortisol decline among women with a current ED were associated with higher levels of psychopathology during pregnancy. Women's cortisol awakening response, CRH and CRH-BP levels did not differ across the three groups. Infants' stress response was also significantly higher among those in the C-ED group, although this effect was attenuated after controlling for confounders.

CONCLUSIONS

During pregnancy women with ED have lower cortisol declines, suggestive of blunted diurnal cortisol rhythms. Postnatally, their infants also have a heightened response to stress. This is the first study to identify HPA axis dysfunction in pregnancy in women with ED, and to show an intergenerational effect. Since dysfunctions in HPA activity during childhood may represent a risk factor for psychological and physical health problems later in life, further investigation of the potential long-term implications of these findings is crucial.

Cardiovascular reactions to psychological stress and abuse history: the role of occurrence, frequency, and type of abuse

BACKGROUND AND OBJECTIVES

Extreme cardiovascular reactions to psychological stress have been associated with traumatic life experiences. Previous studies have focused on the occurrence or frequency of abuse rather than type of abuse. We examined how occurrence, frequency, and the type of abuse history are related to cardiovascular reactivity (CVR) to acute psychological stress.

DESIGN

The study consisted of between group and continuous analyses to examine the association between occurrence, type, and frequency of abuse with cardiovascular reactions to acute psychological stress.

METHODS

Data from 64 participants were collected. Heart rate, systolic blood pressure, and diastolic blood pressure were measured at baseline and during a standard mental arithmetic stress task.

RESULTS

Individuals who experienced abuse showed diminished CVR to acute psychological stress; this was driven specifically by the history of sexual abuse. Frequency of abuse did not relate to stress reactions.

CONCLUSIONS

These findings accord with previous work suggesting a relationship between traumatic life experience and hypoarousal in physiological reactivity and extend previous findings by suggesting the relationship may be driven by sexual abuse.

Hormonal Factors and Disturbances in Eating Disorders

This review summarizes the current state of the literature regarding hormonal correlates of, and etiologic influences on, eating pathology. Several hormones (e.g., ghrelin, CCK, GLP-1, PYY, leptin, oxytocin, cortisol) are disrupted during the ill state of eating disorders and likely contribute to the maintenance of core symptoms (e.g., dietary restriction, binge eating) and/or co-occurring features (e.g., mood symptoms, attentional biases). Some of these hormones (e.g., ghrelin, cortisol) may also be related to eating pathology via links with psychological stress. Despite these effects, the role of hormonal factors in the etiology of eating disorders remains unknown. The strongest evidence for etiologic effects has emerged for ovarian hormones, as changes in ovarian hormones predict changes in phenotypic and genetic influences on disordered eating. Future studies would benefit from utilizing etiologically informative designs (e.g., high risk, behavioral genetic) and continuing to explore factors (e.g., psychological, neural responsivity) that may impact hormonal influences on eating pathology.

A systematic review and meta-synthesis of the effects and experience of mentoring in eating disorders and disordered eating

In this review, we aimed to explore the benefits, effects and experiences of mentoring on those with an eating disorder or disordered eating. After a systematic search of the literature, four papers were included in the review. A qualitative analysis of the papers identified three key themes. The themes were (1) diverse benefits (mentees), (2) finding comfort in belonging (mentees), and (3) affirmation of the transformation they have made (mentors). The experience of mentoring was shown to have value for both mentors and mentees. Mentorship should be further utilized in the areas of eating disorders and disordered eating, as it shows promising reciprocal benefits for both mentor and mentee.

Anxiety symptom interpretation: A potential mechanism explaining the cardiorespiratory fitness-anxiety relationship

BACKGROUND

Higher cardiorespiratory fitness is associated with lower trait anxiety, but research has not examined whether fitness is associated with state anxiety levels and the interpretation of these symptoms. The aim of this paper was to (1) reexamine the association between cardiorespiratory fitness and general anxiety and (2) examine anxiety intensity and perceptions of these symptoms prior to an acute psychological stress task.

METHODS

Participants (N=185; 81% female; Mage=18.04, SD=0.43 years) completed a 10-minute Paced Serial Addition Test. General anxiety was assessed using the anxiety subscale of the Hospital Anxiety Depression Scale. Cognitive and somatic anxiety intensity and perceptions of symptoms was assessed immediately prior to the acute psychological stress task using the Immediate Anxiety Measures Scale. Cardiorespiratory fitness was calculated using a validated standardized formula.

RESULTS

Higher levels of cardiorespiratory fitness were associated with lower levels of general anxiety. Path analysis supported a model whereby perceptions of anxiety symptoms mediated the relationship between cardiorespiratory fitness and levels of anxiety experienced during the stress task; results remained significant after adjusting for general anxiety levels. Specifically, higher levels of cardiorespiratory fitness were positively associated with more positive perceptions of anxiety symptoms and lower levels of state anxiety.

LIMITATIONS

A standard formula rather than maximal testing was used to assess cardiorespiratory fitness, self-report questionnaires were used to assess anxiety, and the study was cross-sectional in design.

CONCLUSIONS

Results suggest a potential mechanism explaining how cardiorespiratory fitness can reduce anxiety levels.

Blunted cardiac stress reactors exhibit relatively high levels of behavioural impulsivity

Blunted physiological reactions to acute psychological stress are associated with a range of adverse health and behavioural outcomes. This study examined whether extreme stress reactors differ in their behavioural impulsivity. Individuals showing blunted (N=23) and exaggerated (N=23) cardiovascular reactions to stress were selected by screening a healthy student population (N=276). Behavioural impulsivity was measured via inhibitory control and motor impulsivity tasks. Blunted reactors exhibited greater impulsivity than exaggerated reactors on both stop-signal, F(1,41)=4.99, p=0.03, ηp(2)=0.108, and circle drawing, F(1,43)=4.00, p=0.05, η p(2)=0.085, tasks. Individuals showing blunted cardiovascular stress reactions are characterized by greater impulsivity which may contribute to their increased susceptibility to outcomes such as obesity and addiction.

Ginseng and Ginkgo Biloba Effects on Cognition as Modulated by Cardiovascular Reactivity: A Randomised Trial

Background

There is some evidence to suggest that ginseng and Ginkgo biloba can improve cognitive performance, however, very little is known about the mechanisms associated with such improvement. Here, we tested whether cardiovascular reactivity to a task is associated with cognitive improvement.

Methodology/Principal findings

Using a double-blind, placebo controlled, crossover design, participants (N = 24) received two doses of Panax Ginseng (500, 1000 mg) or Ginkgo Biloba (120, 240 mg) (N = 24), and underwent a series of cognitive tests while systolic, diastolic, and heart rate readings were taken. Ginkgo Biloba improved aspects of executive functioning (Stroop and Berg tasks) in females but not in males. Ginseng had no effect on cognition. Ginkgo biloba in females reversed the initial (i.e. placebo) increase in cardiovascular reactivity (systolic and diastolic readings increased compared to baseline) to cognitive tasks. This effect (reversal) was most notable after those tasks (Stroop and Iowa) that elicited the greatest cardiovascular reactivity during placebo. In males, although ginkgo also decreased cardiovascular readings, it did so from an initial (placebo) blunted response (i.e. decrease or no change from baseline) to cognitive tasks. Ginseng, on the contrary, increased cardiovascular readings compared to placebo.

Conclusions/Significance

These results suggest that cardiovascular reactivity may be a mechanism by which ginkgo but not ginseng, in females is associated with certain forms of cognitive improvement.

Trial Registration

ClinicalTrials.gov NCT02386852

Heart rate complexity: A novel approach to assessing cardiac stress reactivity

Correlation dimension (D2), a measure of heart rate (HR) complexity, has been shown to decrease in response to acute mental stress and relate to adverse cardiovascular health. However, the relationship between stress-induced changes in D2 and HR has yet to be established. The present studies aimed to assess this relationship systematically while controlling for changes in respiration and autonomic activity. In Study 1 (N = 25) D2 decreased during stress and predicted HR reactivity even after adjusting for changes in respiration rate, and cardiac vagal tone. This result was replicated in Study 2 (N = 162) and extended by including a measure of cardiac sympathetic activity; correlation dimension remained an independent predictor of HR reactivity in a hierarchical linear model containing measures of cardiac parasympathetic and sympathetic activity and their interaction. These results suggest that correlation dimension may provide additional information regarding cardiac stress reactivity above that provided by traditional measures of cardiac autonomic function.

Behavioral and neurodevelopmental precursors to binge-type eating disorders: support for the role of negative valence systems

BACKGROUND

Pediatric loss-of-control (LOC) eating is a robust behavioral precursor to binge-type eating disorders. Elucidating precursors to LOC eating and binge-type eating disorders may refine developmental risk models of eating disorders and inform interventions.

METHOD

We review evidence within constructs of the Negative Valence Systems (NVS) domain, as specified by the Research Domain Criteria framework. Based on published studies, we propose an integrated NVS model of binge-type eating-disorder risk.

RESULTS

Data implicate altered corticolimbic functioning, neuroendocrine dysregulation, and self-reported negative affect as possible risk factors. However, neuroimaging and physiological data in children and adolescents are sparse, and most prospective studies are limited to self-report measures.

CONCLUSIONS

We discuss a broad NVS framework for conceptualizing early risk for binge-type eating disorders. Future neural and behavioral research on the developmental trajectory of LOC and binge-type eating disorders is required.

Central mechanisms regulating coordinated cardiovascular and respiratory function during stress and arousal

Actual or potentially threatening stimuli in the external environment (i.e., psychological stressors) trigger highly coordinated defensive behavioral responses that are accompanied by appropriate autonomic and respiratory changes. As discussed in this review, several brain regions and pathways have major roles in subserving the cardiovascular and respiratory responses to threatening stimuli, which may vary from relatively mild acute arousing stimuli to more prolonged life-threatening stimuli. One key region is the dorsomedial hypothalamus, which receives inputs from the cortex, amygdala, and other forebrain regions and which is critical for generating autonomic, respiratory, and neuroendocrine responses to psychological stressors. Recent studies suggest that the dorsomedial hypothalamus also receives an input from the dorsolateral column in the midbrain periaqueductal gray, which is another key region involved in the integration of stress-evoked cardiorespiratory responses. In addition, it has recently been shown that neurons in the midbrain colliculi can generate highly synchronized autonomic, respiratory, and somatomotor responses to visual, auditory, and somatosensory inputs. These collicular neurons may be part of a subcortical defense system that also includes the basal ganglia and which is well adapted to responding to threats that require an immediate stereotyped response that does not involve the cortex. The basal ganglia/colliculi system is phylogenetically ancient. In contrast, the defense system that includes the dorsomedial hypothalamus and cortex evolved at a later time, and appears to be better adapted to generating appropriate responses to more sustained threatening stimuli that involve cognitive appraisal.

Problematic Internet use, excessive alcohol consumption, their comorbidity and cardiovascular and cortisol reactions to acute psychological stress in a student population

BACKGROUND AND AIMS

Problematic Internet use and excessive alcohol consumption have been associated with a host of maladaptive outcomes. Further, low (blunted) cardiovascular and stress hormone (e.g. cortisol) reactions to acute psychological stress are a feature of individuals with a range of adverse health and behavioural characteristics, including dependencies such as tobacco and alcohol addiction. The present study extended this research by examining whether behavioural dependencies, namely problematic Internet use, excessive alcohol consumption, and their comorbidity would also be associated with blunted stress reactivity.

METHODS

A large sample of university students (N = 2313) were screened using Internet and alcohol dependency questionnaires to select four groups for laboratory testing: comorbid Internet and alcohol dependence (N = 17), Internet dependence (N = 17), alcohol dependence (N = 28), and non-dependent controls (N = 26). Cardiovascular activity and salivary cortisol were measured at rest and in response to a psychological stress protocol comprising of mental arithmetic and public speaking tasks.

RESULTS

Neither problematic Internet behaviour nor excessive alcohol consumption, either individually or in combination, were associated with blunted cardiovascular or cortisol stress reactions. Discussion It is possible that problematic Internet behaviour and excessive alcohol consumption in a student population were not related to physiological reactivity as they may not reflect ingrained addictions but rather an impulse control disorder and binging tendency.

CONCLUSIONS

The present results serve to indicate some of the limits of the developing hypothesis that blunted stress reactivity is a peripheral marker of the central motivational dysregulation in the brain underpinning a wide range of health and behavioural problems.

Cardiovascular and cortisol reactions to acute psychological stress under conditions of high versus low social evaluative threat: associations with the type D personality construct

OBJECTIVES

Social evaluative threat is an important factor in the cardiovascular response to mental stress. This study examined whether Type D personality, characterized by social inhibition and negative affectivity, is associated with an adverse cardiovascular response to a non-social and social evaluative threat.

METHODS

A total of 2300 students were screened for Type D personality, and 130 were selected for a nonsocial stress exposure condition (31 Type D, 30 non-Type D: 52% female) or a condition high in social evaluative threat (35 Type D, 34 non-Type D: 55% female). Systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), and salivary cortisol were measured.

RESULTS

Social evaluative threat resulted in higher cardiovascular responses than the nonsocial challenge (SBP, p = .001, η = 0.092;DBP, p = .006, η = 0.058;HR, p = .006, η = 0.059). The greatest cardiovascular stress reactions were exhibited by Type D participants in the high social evaluation condition; reflected in significant group by condition interactions for SBP (F(1,126) = 7.29, p = .008, η = 0.055), DBP (F(1,126) = 5.23, p = .024, η = 0.040), and HR (F(1,126) = 5.04, p = .027, η = 0.038) reactivity. Only Type Ds in the social condition mounted a positive cortisol response (F(1,33) = 5.07, p = .031, η = 0.133).

CONCLUSIONS

Type D individuals show different stress reactions depending on the social evaluative nature of the stress exposure. These findings suggest that dysregulation of the stress response in social situations potentially increases cardiovascular disease risk.

Blunted neuroendocrine stress reactivity in young women with eating disorders

OBJECTIVE

Stress is known to influence risk and progression of eating disorders (EDs). However, studies investigating physiological and psychological stress responses under laboratory conditions in patients with Anorexia nervosa or Bulimia nervosa are scarce and often produce conflicting findings. We therefore aimed to compare the neuroendocrine and affective stress response in ED inpatients and healthy controls.

METHODS

Twenty-eight female inpatients with Anorexia or Bulimia nervosa and 26 healthy women were exposed to the Trier Social Stress Test (TSST). Salivary cortisol and alpha-amylase (sAA) levels were assessed before as well as repeatedly after stress exposure, while heart rate and heart rate variability were determined before and during the TSST. Negative affective state was assessed at baseline and post-TSST.

RESULTS

Compared to healthy controls, ED patients showed blunted cortisol stress responses combined with overall attenuated sAA levels. The latter was reflected in generally enhanced parasympathetic activity indicated by lower heart rate and stronger high-frequency heart rate variability throughout the TSST. Although patients reported more negative affect overall, they did not differ in their affective stress response.

CONCLUSIONS

In summary, patients suffering from eating disorders show a blunted HPA axis reactivity to stress exposure and a generally reduced sympathetic/exaggerated parasympathetic nervous system activity. This combination may contribute to elevated health risks seen in eating disorder patients, such as enhanced inflammatory activity, and thus provide insight into the underlying stress-related mechanisms.

Evidence for a compulsive-like behavior in rats exposed to alternate access to highly preferred palatable food

Converging evidence suggests that recurrent excessive calorie restriction causes binge eating by promoting behavioral disinhibition and overeating. This interpretation suggests that cognitive adaptations may surpass physiological regulations of metabolic needs after recurrent cycles of dieting and binging. Intermittent access to palatable food has long been studied in rats, but the consequences of such diet cycling procedures on the cognitive control of food seeking remain unclear. Female Wistar rats were divided in two groups matched for food intake and body weight. One group received standard chow pellets 7 days/week, whereas the second group was given chow pellets for 5 days and palatable food for 2 days over seven consecutive weeks. Rats were also trained for operant conditioning. Intermittent access to palatable food elicited binging behavior and reduced intake of normal food. Rats with intermittent access to palatable food failed to exhibit anxiety-like behaviors in the elevated plus maze, but displayed reduced locomotor activity in the open field and developed a blunted corticosterone response following an acute stress across the diet procedure. Trained under a progressive ratio schedule, both groups exhibited the same motivation for sweetened food pellets. However, in contrast to controls, rats with a history of dieting and binging exhibited a persistent compulsive-like behavior when access to preferred pellets was paired with mild electrical foot shock punishments. These results highlight the intricate development of anxiety-like disorders and cognitive deficits leading to a loss of control over preferred food intake after repetitive cycles of intermittent access to palatable food.

Neuroendocrine and cardiovascular reactions to acute psychological stress are attenuated in smokers

A number of studies have now examined the association between smoking and the magnitude of physiological reactions to acute psychological stress. However, no large-scale study has demonstrated this association incorporating neuroendocrine in addition to cardiovascular reactions to stress. The present study compared neuroendocrine and cardiovascular reactions to acute stress exposure in current smokers, ex-smokers, and those who had never smoked in a large community sample. Salivary cortisol, systolic and diastolic blood pressure, heart rate and frequency components of systolic blood pressure and heart rate variability were measured at rest and during exposure to a battery of three standardized stress tasks in 480 male and female participants from the Dutch Famine Birth Cohort Study. Current smokers had significantly lower cortisol, systolic and diastolic blood pressure, and heart rate reactions to stress. They also exhibited smaller changes in the low frequency band of blood pressure variability compared to ex- and never smokers. There were no group differences in stress related changes in overall heart rate variability as measured by the root mean square of successive interbeat interval differences or in the high frequency band of heart rate variability. In all cases, effects remained significant following statistical adjustment for a host of variables likely to be associated with reactivity and/or smoking. In secondary analyses, there were no significant associations between lifetime cigarette consumption or current consumption and stress reactivity. In conclusion, compared to non-smokers and ex-smokers, current smokers exhibited attenuated neuroendocrine and cardiovascular reactions to acute psychological stress. Among smokers and ex-smokers, there is no evidence that lifetime exposure was associated with physiological reactions to acute stress, nor that current levels of cigarette consumption were associated with reactivity. It is possible, then, that attenuated stress reactivity may be a marker for an increased susceptibility to take up and/or maintain smoking behaviour once initiated.

Rated and measured impulsivity in children is associated with diminished cardiac reactions to acute psychological stress

This study examined the association between impulsivity and heart rate reactions to a brief psychological stress in pre-adolescent children. Impulsivity was assessed by two response inhibition tasks and maternal self-report. Heart rate was measured at rest and in response to a mental arithmetic challenge. Children high in impulsivity showed blunted cardiac stress reactions. This result resonates with previous findings that blunted stress reactivity is characteristic of a range of problematic behaviours often associated with impulsivity.

Latino children's body mass index at 2-3.5 years predicts sympathetic nervous system activity at 5 years

BACKGROUND

To understand whether the relationship between young children's autonomic nervous system (ANS) responses predicted their BMI, or vice versa, the association between standardized BMI (zBMI) at 2, 3.5, and 5 years of age and ANS reactivity at 3.5-5 years of age, and whether zBMI predicts later ANS reactivity or whether early ANS reactivity predicts later zBMI, was studied.

METHODS

Low-income, primarily Latino children (n=112) were part of a larger cohort study of mothers recruited during early pregnancy. Study measures included maternal prenatal weight, children's health behaviors (i.e., time watching television, fast food consumption, and time playing outdoors), children's height and weight at 2, 3.5, and 5 years, and children's ANS reactivity at 3.5 and 5 years. ANS measures of sympathetic nervous system (i.e., pre-ejection period) and parasympathetic nervous system (i.e., respiratory sinus arrhythmia) activity were monitored during rest and four challenges. Reactivity was calculated as the difference between mean challenge response and rest. Structural equation models analyzed the relationship between children's zBMI at 2, 3.5, and 5 years and ANS reactivity at 3.5 and 5 years, adjusting for mother's BMI, children's behaviors, and changes in height.

RESULTS

There was no association between zBMI and ANS cross-sectionally. Children with high zBMI at 2 or 3.5 years or large zBMI increases from 2 to 3.5 years of age had decreased sympathetic activity at 5 years. Neither sympathetic nor parasympathetic reactivity at 3.5 years predicted later zBMI.

CONCLUSIONS

Increased zBMI early in childhood may dampen young children's SNS responses later in life.

Binge-like eating attenuates nisoxetine feeding suppression, stress activation, and brain norepinephrine activity

Stress is often associated with binge eating. A critical component of the control of stress is the central norepinephrine system. We investigated how dietary-induced binge eating alters central norepinephrine and related behaviors. Young male Sprague Dawley rats received calorie deprivation (24 h) and /or intermittent sweetened fat (vegetable shortening with sucrose; 30 min) twice a week for 10 weeks. The groups were Restrict Binge (calorie deprivation/sweetened fat), Binge (sweetened fat), Restrict (calorie deprivation), and Naive (no calorie deprivation/no sweetened fat). Dietary-induced binge eating was demonstrated by Restrict Binge and Binge, which showed an escalation in 30-min intake over time. Feeding suppression following nisoxetine (3 mg/kg; IP), a selective norepinephrine reuptake inhibitor, was not evident in Restrict Binge (Restrict Binge: 107±13, Binge: 52±9, Restrict: 80±8, Naive: 59±13% of saline injection at 1 h). In subsequent experiments with Restrict Binge and Naive, Restrict Binge had reduced corticosterone (Restrict Binge: 266±25; Naive: 494±36 ng/ml) and less feeding suppression (Restrict Binge: 81±12, Naive: 50±11% of non-restraint intake at 30 min) following restraint stress (1 h). Dietary-induced binge eating in Restrict Binge was not altered by a dorsal noradrenergic bundle lesion caused by N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4), but frontal cortex norepinephrine was positively correlated with the average 30-min intake post-lesion (0.69; p<0.01). In a separate set of animals, single-unit in vivo electrophysiological recording of locus coeruleus–norepinephrine neural activity demonstrated reduced sensory-evoked response as a consequence of the Restrict Binge schedule (Restrict Binge: 8.1±0.67, Naive: 11.9±1.09 Hz). These results, which suggest that a consequence of dietary-induced binge eating is to attenuate the responsiveness of the brain norepinephrine system, will further our understanding of how highly palatable foods dampen the stress neuraxis.

Disordered eating behaviors in young adult Mexican American women: prevalence and associations with health risks

Recent research has shown that disordered eating behaviors are as prevalent in heterogenous samples of Latinas living in the U.S. as in non-Hispanic white women, yet less is known about the prevalence in women of Mexican origin. The primary purpose of this study is to report the prevalence and associations among DE behaviors and health risk of alcohol, tobacco use and obesity in a sample of N = 472 young adult college enrolled Mexican American (MA) women living in the United States. This report focuses on baseline data from a 12-month repeated measures longitudinal study. Ecological momentary assessment (EMA) was used to capture the prevalence of disordered eating and health risk behaviors in the context of everyday activities. Disordered eating behaviors including purging, binge eating, fasting and exercise were reported by approximately 15% of the sample. Food/calorie restricting, was the most prevalent behavior reported by 48% of the sample and along with binge eating was a positive predictor of BMI. Fasting was the only disordered eating behavior associated with tobacco use. These findings suggest that subclinical levels of DE behaviors are prevalent in a community sample of women of Mexican origin and are associated with health risks of tobacco use and higher BMI. Early identification of DE behaviors and community-based interventions targeting MA women may help reduce disparities associated with overweight and obesity in this population.

Increases in weight during chronic stress are partially associated with a switch in food choice towards increased carbohydrate and saturated fat intake

We examined if stress associated changes in weight and dietary restraint are associated with changes in the composition of foods consumed. Participants were 38 healthy women on a taught postgraduate university course. Data were obtained at the beginning of the semester and 15 weeks later just prior to a written course exam (the stressor). By using a within subject design, we measured the composition of food consumed, body mass index (BMI), levels of dietary restraint and salivary cortisol. In the larger study from which these data were obtained, it was shown that the effect of increased cortisol secretion on weight gain was mediated by a reduction in dietary restraint. The present data show that increased cortisol secretion, reduced dietary restraint and increased caloric intake, account for 73% of the variance in change in BMI. Further regression analysis indicated that the change in dietary restraint mediated the effect of change in cortisol on change in BMI. Final analysis revealed that the effect of these changes in dietary restraint on weight are partially mediated by increased caloric intake from carbohydrate and saturated fat, that is, a change in dietary composition partially accounts for the link between increased cortisol secretion through heightened hypothalamic-pituitary-adrenal activity resulting in weight gain. These data are consistent with a 'comfort food hypothesis', as they suggest that chronic stress can promote reward associated behaviour through reduced dietary restraint and consumption of food containing more carbohydrate and saturated fat.

Is blunted cardiovascular reactivity in depression mood-state dependent? A comparison of major depressive disorder remitted depression and healthy controls

Prior work has repeatedly demonstrated that people who have current major depression exhibit blunted cardiovascular reactivity to acute stressors (e.g., Salomon et al., 2009). A key question regards the psychobiological basis for these deficits, including whether such deficits are depressed mood-state dependent or whether these effects are trait-like and are observed outside of depression episodes in vulnerable individuals. To examine this issue, we assessed cardiovascular reactivity to a speech stressor task and a forehead cold pressor in 50 individuals with current major depressive disorder (MDD), 25 with remitted major depression (RMD), and 45 healthy controls. Heart rate (HR), blood pressure and impedance cardiography were assessed and analyses controlled for BMI and sex. Significant group effects were found for SBP, HR, and PEP for the speech preparation period and HR, CO, and PEP during the speech. For each of these parameters, only the MDD group exhibited attenuated reactivity as well as impaired SBP recovery. Reactivity and recovery in the RMD group more closely resembled the healthy controls. Speeches given by the MDD group were rated as less persuasive than the RMD or healthy controls' speeches. No significant differences were found for the cold pressor. Blunted cardiovascular reactivity and impaired recovery in current major depression may be mood-state dependent phenomena and may be more reflective of motivational deficits than deficits in the physiological integrity of the cardiovascular system.

Personality and physiological reactions to acute psychological stress

Stable personality traits have long been presumed to have biological substrates, although the evidence relating personality to biological stress reactivity is inconclusive. The present study examined, in a large middle aged cohort (N=352), the relationship between key personality traits and both cortisol and cardiovascular reactions to acute psychological stress. Salivary cortisol and cardiovascular activity were measured at rest and in response to a psychological stress protocol comprising 5min each of a Stroop task, mirror tracing, and a speech task. Participants subsequently completed the Big Five Inventory to assess neuroticism, agreeableness, openness to experience, extraversion, and conscientiousness. Those with higher neuroticism scores exhibited smaller cortisol and cardiovascular stress reactions, whereas participants who were less agreeable and less open had smaller cortisol and cardiac reactions to stress. These associations remained statistically significant following adjustment for a range of potential confounding variables. Thus, a negative personality disposition would appear to be linked to diminished stress reactivity. These findings further support a growing body of evidence which suggests that blunted stress reactivity may be maladaptive.